Head and neck hypervascular lesions: embolization with ethylene vinyl alcohol copolymer--laboratory evaluation in Swine and clinical evaluation in humans.

PURPOSE: (a) To assess in swine long-term (12-month) histopathologic changes, particularly, those related to recanalization and angiotoxicity after endovascular delivery of ethylene vinyl alcohol copolymer (EVAC), and (b) to evaluate initial clinical experience in 18 patients with head and neck tumors and arteriovenous malformations. MATERIALS AND METHODS: Embolization with EVAC was performed in one rete each in five swine. After 12 months, an angiogram was obtained, and the contralateral rete was also embolized (acute). Swine were sacrificed and the retia harvested for pathologic examination. In the clinical study, 18 patients with tumors (n = 14), facial arteriovenous malformations (n = 3), and vertebral arteriovenous fistula (n = 1) underwent therapeutic embolization. The technical aspects of EVAC embolization, percentage of occlusion, and clinical complications were evaluated. RESULTS: Angiographic 12-month follow-up in swine revealed persistent occlusion of the embolized rete or retia. Histologic examination of the same rete showed vascular occlusion and moderate intraluminal foreign body giant cell reaction; the acutely embolized rete showed no endothelial denudation or angionecrosis. Clinical evaluation in patients revealed satisfactory penetration of lesion vasculature with EVAC when the microcatheter was advanced within 2 cm of a lesion or when percutaneous puncture was performed. There were two transient complications: one increase in a preexisting fifth nerve palsy and one increase in preexisting hemiparesis. CONCLUSION: EVAC is a promising liquid embolic material providing long-term occlusion of blood vessels.

Intraarterial chemotherapy for brain tumors by using a spatial dose fractionation algorithm and pulsatile delivery.

PURPOSE: To evaluate the cause of complications in intraarterial chemotherapy for brain tumors and validate a dosage algorithm based on arterial territory. MATERIALS AND METHODS: Four hundred sixty-two procedures were performed in 113 patients. Technique included pulsatile infusion of a chemotherapeutic agent. Dosage was calculated per hemisphere and divided per arterial territory according to a spatial dose fractionation algorithm based on the vascular territories of major cerebral arteries: middle cerebral artery, 60%; anterior cerebral artery, 20%; posterior cerebral artery, 15%; and perforator arteries, 5%. Hospital charts of all patients were retrospectively reviewed for complications, with specific attention given to the angiograms to determine a cause. Then, subgroup analysis of the chemotherapy protocol with the largest patient population was performed to evaluate predictors of complications. RESULTS: Six (1.3%) complications were asymptomatic; 12 (2.6%), transient neurologic; three (0.6%), permanent minor neurologic; three (0.6%), permanent major neurologic; and 32 (7.0%), seizures. In the subgroup analysis, the hemispheric dose administered according to the algorithm was strongly predictive of seizure and neurologic deficit. CONCLUSION: Neurotoxicity of intraarterial cerebral chemotherapy can be minimized by using pulsatile injection and the described spatial dose fractionation algorithm.